Rotational apparatus unit

ABSTRACT

A rotational apparatus unit includes a compressor and a motor-generator. The compressor has a housing and a drive shaft supported by the housing. The motor-generator drives the drive shaft in accordance with electric current supplied from outside. The motor-generator is located on a periphery of the housing of the compressor such that an axis of the motor-generator is coaxial with an axis of the drive shaft.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a rotational apparatus unit that is provided with a rotational apparatus and a motor, which are used as auxiliary devices of a vehicle engine.

[0002] Japanese Unexamined Utility Model Publication No. 6-87678 discloses a rotational apparatus unit that includes a compressor, which forms a refrigeration cycle, and a motor. When an engine is running, power transmission from the engine drives the compressor and the motor. The motor generates electric power, accordingly. When the engine is not running, current is supplied to the motor from outside. This activates the motor, which then drives the compressor. The motor functions as a generator, which generates electricity, and a power source, which generates power.

[0003] In the disclosed rotational apparatus unit, the drive shaft of the compressor and the drive shaft of the motor are axially aligned. Therefore, the rotational apparatus unit is long in the axial direction of the drive shaft. For an auxiliary device of a vehicle engine, the increase of size in the axial direction is undesirable.

SUMMARY OF THE INVENTION

[0004] The objective of the present invention is to provide a rotational apparatus unit that is miniaturized in the axial direction of a drive shaft.

[0005] To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, A rotational apparatus unit is provided. The rotational apparatus has a rotational apparatus and a motor. The rotational apparatus has a housing and a rotary shaft supported by the housing. The motor drives the rotary shaft in accordance with electric current supplied from outside. The motor is located on a periphery of the housing of the rotational apparatus such that an axis of the motor is coaxial with an axis of the rotary shaft.

[0006] The present invention also provides a rotational apparatus unit connected to an engine via a power transmission mechanism. The rotational apparatus unit has a rotational apparatus and a generator. The rotational apparatus has a housing and a rotary shaft supported by the housing. The rotary shaft rotates by power of the engine. The generator is driven by power of the engine for generating electricity. The generator is located on the periphery of the housing of the rotational apparatus such that an axis of the generator is coaxial with an axis of the rotary shaft.

[0007] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawing in which:

[0009]FIG. 1 is a cross-sectional view of a rotational apparatus unit of one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A rotational apparatus unit provided on a vehicle according to one embodiment of the present invention will be described with reference to FIG. 1.

[0011] Summary of Rotational Apparatus Unit

[0012] The rotational apparatus unit includes a swash plate type variable displacement compressor CP, which forms a refrigeration cycle of a vehicle air-conditioning system, and a motor-generator MG. The rotational apparatus unit is operably connected to an internal combustion engine Eg, which is a power source of a vehicle, through a power transmission mechanism PT.

[0013] When the engine Eg is running, power transmission from the engine EG drives the compressor CP. Thus, refrigerant gas is compressed. Power transmission from the engine EG also drives the motor-generator MG, which then generates electricity. When the engine Eg is not running, the compressor CP and the motor-generator MG are disengaged from the engine Eg. In this state, current is supplied from outside and the motor-generator MG generates power. This drives the compressor CP.

[0014] Compressor CP

[0015] The compressor CP includes a cylinder block 1, a front housing member 2, and a rear housing member 4. The front housing member 2 is secured to the front end of the cylinder block 1. The rear housing member 4 is secured to the rear end of the cylinder block 1. A valve plate assembly 3 is secured between the cylinder block 1 and the rear housing member 4. The cylinder block 1, the front housing member 2, and the rear housing member 4 form the housing assembly of the compressor CP. In FIG. 1, the left side of the figure is defined as the front, and the right side of the figure is defined as the rear.

[0016] A crank chamber 5 is defined between the cylinder block 1 and the front housing member 2. A drive shaft 6 extends through the crank chamber 5 and rotatably supported by the cylinder block 1 and the front housing member 2. The front end of the drive shaft 6 projects from the front wall of the front housing member 2. A cylindrical small diameter portion 2 a is provided on the front wall of the front housing member 2 to surround the front end portion of the drive shaft 6. A portion of the front housing 2 other than the small diameter portion 2 a is a large diameter portion 2 b.

[0017] A lug plate 11 is located in the crank chamber 5 and is secured to the drive shaft 6 to integrally rotate with the drive shaft 6. A swash plate 12 is accommodated in the crank chamber 5. The swash plate 12 is supported by the drive shaft 6 to slide along and incline with respect to the axis L. A hinge mechanism 13 is arranged between the lug plate 11 and the swash plate 12. Accordingly, the swash plate 12 rotates integrally with the lug plate 11 and the drive shaft 6 by means of the hinge mechanism 13.

[0018] Cylinder bores 1 a (only one of the cylinder bores is shown in FIG. 1) are formed in the cylinder block 1 to encompass the axis L of the drive shaft 6 at equal angular intervals. Each cylinder bore 1 a is formed through the cylinder block 1. A single-headed piston 20 is housed in each cylinder bore 1 a. The valve plate assembly 3 and each piston 20 closes the openings of each cylinder bore 1 a. A compression chamber is defined in each cylinder bore 1 a. The volume of the compression chamber varies as each piston 20 reciprocates in the corresponding cylinder bore 1 a. Each piston 20 is coupled to the periphery of the swash plate 12 by a pair of shoes 19. Therefore, when the swash plate 12 rotates integrally with the drive shaft 6, rotation of the swash plate 12 reciprocates each piston 20 by means of the pair of shoes 19.

[0019] The drive shaft 6, the lug plate 11, the hinge mechanism 13, the swash plate 12, the shoes 19, the pistons 20, and the cylinder bores 1 a form the compression mechanism, which performs the main function of the compressor CP. The large diameter portion 2 b forms a large diameter main housing member that accommodates the compression mechanism.

[0020] A suction chamber 21 and a discharge chamber 22 are respectively defined between the valve plate assembly 3 and the rear housing member 4. When each piston 20 moves from the top dead center to the bottom dead center, the refrigerant in the suction chamber 21 is drawn into the corresponding cylinder bore 1 a, or the corresponding compression chamber, through a suction port 23 and a suction valve 24 formed in the valve plate assembly 3. The refrigerant gas drawn into each cylinder bore 1 a is compressed to a predetermined pressure by the movement of the corresponding piston 20 from the bottom dead center to the top dead center. The compressed refrigerant is then discharged to the discharge chamber 22 through a discharge port 25 and a discharge valve 26 formed in the valve plate assembly 3.

[0021] The crank chamber 5 and the suction chamber 21 are connected by a bleed passage 27. The discharge chamber 22 and the crank chamber 5 are connected by a supply passage 28. An electromagnetic valve 29 is located in the supply passage 28. The electromagnetic valve 29 has a valve body 29 a and a solenoid 29 b, which drives the valve body 29 a.

[0022] The solenoid 29 b changes the position of the valve body 29 a of the electromagnetic valve 29, or the opening degree, in accordance with the amount of current supplied from outside. The flow rate of highly pressurized discharge gas that is conducted to the crank chamber 5 from the discharge chamber 22 through the supply passage 28 is set by adjusting the opening degree. The internal pressure of the crank chamber 5 is determined by the relationship between the flow rate of gas entering the crank chamber 5 and the flow rate of gas that is flowing from the crank chamber 5 into the suction chamber 21 through the bleed passage 27. The difference between the internal pressure of the crank chamber 5 and the internal pressure of each cylinder bore 1 a changes according to the internal pressure of the crank chamber 5. The inclination angle of the swash plate 12 is determined by this pressure difference. As a result, the stroke of each piston 20, or the displacement, is adjusted.

[0023] The discharge chamber 22 and the suction chamber 21 are connected by an external refrigerant circuit 30, which forms the refrigeration cycle together with the compressor CP. The external refrigerant circuit 30 includes, for example, a condenser 31, an expansion valve 32, which serves as decompression device, and an evaporator 33.

[0024] Power Transmission Mechanism PT

[0025] A rotor 36 is rotatably supported around the outer circumferential portion of the small diameter portion 2 a of the front housing member 2 through a bearing 35. The front end of the rotor 36 is coupled to the front end of the drive shaft 6 through a damper mechanism 37. The rotor 36 and the drive shaft 6 rotate integrally. When power is transmitted between the rotor 36 and the drive shaft 6, the damper mechanism 37 reduces torque variation by its elasticity and prevents the transmission of excessive torque.

[0026] A pulley 38 is rotatably supported around the outer circumferential portion of a small diameter portion 36 a of the rotor 36 through a bearing 39. The small diameter portion 36 a will be described in detail later. The pulley 38 and the rotor 36 serve as rotors that form the power transmission mechanism. A belt 40, which extends from the output shaft (not shown) of the engine Eg, is located around the pulley 38. Thus, the pulley 38 is always driven when the engine Eg is running.

[0027] A well known roller type one-way clutch 41 is embedded in the bearing 39. The one-way clutch 41 permits the power transmission from the pulley 38 to the rotor 36 and prevents the power transmission from the rotor 36 to the pulley 38. That is, the one-way clutch 41 is a mechanical device, which reliably permits power transmission from the engine Eg to the compressor CP and the motor-generator MG, and prevents power transmission from the motor-generator MG to the engine Eg. The one-way clutch 41 includes a roller 41 a and a cam surface 41 b.

[0028] Motor-Generator MG

[0029] The rear end of the rotor 36 extends from the position in the vicinity of the outer circumferential portion of the small diameter portion 2 a of the front housing member 2 along the front wall of the front housing member 2 to the position in the vicinity of the outer circumferential portion of the large diameter portion 2 b of the front housing member 2. More specifically, the rotor 36 includes a cylindrical small diameter portion 36 a, a cylindrical large diameter portion 36 b, and connecting portions 36 c. The small diameter portion 36 a of the rotor 36 is arranged around the outer circumferential portion of the small diameter portion 2 a of the front housing member 2. The large diameter portion 36 b of the rotor 36 is arranged around the outer circumferential portion of the large diameter portion 2 b of the front housing member 2. The connecting portions 36 c connect the small diameter portion 36 a and the large diameter portion 36 b of the rotor 36. Each connecting portion 36 c is formed into a fin shaped member. Each connecting portion 36 c radiates out from the rear end of the small diameter portion 36 a of the rotor 36 about an axis L of the drive shaft 6. When the rotor 36 rotates, each connecting portion 36 c functions as a fan, which generates air flow along the axis L around the housing assembly of the compressor CP.

[0030] Magnets 45 are fixed to the inner circumferential surface of the large diameter portion 36 b of the rotor 36. The magnets 45 are equally spaced apart around the axis L of the drive shaft 6. A flange 44 is integrally formed on the outer circumferential surface of the large diameter portion 2 b of the front housing member 2 and extends radially outward. The flange 44 functions as a housing member for the motor-generator MG. The flange, or the motor housing member 44, has bolt holes 44 c. The motor housing member 44 functions as a bracket for installing the rotational apparatus unit to a vehicle.

[0031] The motor housing member 44 includes an annular space 44 a, which is located around the axis L of the drive shaft 6. The space 44 a is open toward the front of the compressor CP, or the magnets 45. Coils 47 are arranged in the space 44 a such that each coil 47 is opposite to one of the magnet 45 in the axial direction of the drive shaft 6 and the distance between each coil 47 and the corresponding magnet 45 is narrow. The coils 47 are equally spaced apart around the axis L of the drive shaft 6. When current is supplied to the coils 47, the rotor 36 rotates. When the rotor 36, or the magnets 45, rotates, electricity is generated in the coils 47. In the preferred embodiment, a flat rotor type motor-generator MG is used.

[0032] A controller 49 includes an inverter 49 a and a converter 49 b. The controller 49 is located on the outer circumferential surface of the cylinder block 1 and at the rear of the motor-generator MG. As indicated by a thick arrow in FIG. 1, the inverter 49 a and the converter 49 b of the controller 49 are located in the path between the coils 47 of the motor-generator MG and a battery 50. The battery 50 supplies current to the electromagnetic valve 29 and other electrical components of the vehicle.

[0033] A control ventilation path 48 extends along the axis L of the drive shaft 6 between the controller 49 and the cylinder block 1. Motor ventilation paths 44 b are formed through the motor housing member 44. Part of the motor ventilation paths 44 b corresponds to the controller ventilation path 48. As indicated by an arrow in FIG. 1, when the rotor 36, or the connecting portions 36 c, rotates, air flows from the rear of the housing assembly of the compressor CP through both the motor and controller ventilation paths 44 b, 48 to the front of the housing assembly of the compressor CP. As a result, the controller 49, particularly, the inverter 49 a and the converter 49 b, and the motor-generator MG, particularly, the magnets 45 and the coils 47, are cooled by the air.

[0034] When the engine Eg is running, the controller 49 activates the motor-generator MG to function as a generator. Then, the controller 49 converts the alternating current, which is generated by the motor-generator MG, to the direct current using the inverter 49 a. The controller 49 lowers the voltage of the direct current using the converter 49 b and stores the current in the battery 50.

[0035] If the vehicle compartment needs to be cooled when the engine Eg is not running, the controller 49 obtains direct current from the battery 50 and converts the direct current to alternating current using the inverter 49 a. The controller 49 supplies the current to the motor-generator MG through the converter 49 b. This activates the motor-generator MG to function as a power source and drives the compressor CP. Therefore, the vehicle compartment is cooled even when the engine Eg is not running.

[0036] The preferred embodiment provides the following advantages.

[0037] The motor-generator MG is located coaxial with the axis L of the drive shaft 6 at the outer circumferential portion of the front housing member 2 of the compressor CP. Therefore, the rotational apparatus unit is miniaturized in the direction of axis L.

[0038] The motor-generator MG, or at least the magnets 45 and the coils 47, is arranged to surround the large diameter portion 2 b of the front housing member 2 of the compressor CP. Therefore, in comparison to when the motor-generator MG, or the magnets 45 and the coils 47, is arranged to surround the small diameter portion 2 a of the front housing member 2 of the compressor CP, the space for the damper mechanism 37 and the one-way clutch 41 is easily obtained.

[0039] The power transmission mechanism PT has the one-way clutch 41, which permits power transmission from the engine Eg to the motor-generator MG and the compressor CP and prevents the power transmission from the motor-generator MG to the Engine Eg. The one-way clutch 41 is a mechanical device. Therefore, in comparison to when the power transmission is controlled by turning on and off an electromagnetic clutch, the present invention does not require a structure for controlling the electromagnetic clutch by the current supplied from outside. Thus, the structure of the rotational apparatus unit is simplified and the power consumption of the unit is reduced.

[0040] The controller 49 is secured to the housing assembly of the compressor CP. This facilitates the handling of the controller 49 during the installation of the rotational apparatus unit to a vehicle.

[0041] The flat rotor type motor-generator MG is used in the preferred embodiment. In comparison to the other type of motor, the flat rotor type motor-generator MG more reliably miniaturizes the rotational apparatus unit in the direction of axis L.

[0042] The present invention may be modified as follows.

[0043] The motor-generator MG may only function as a power source for the compressor.

[0044] The motor-generator MG may only function as a generator.

[0045] The motor-generator MG may be an outer rotor type motor, in which the magnets 45 are arranged around the coils 47, or an inner rotor type motor, in which the magnets 45 are arranged in the coils 47.

[0046] The one-way clutch may be changed to a clutch other than the roller type clutch used in the preferred embodiment such as a cam type clutch (sprag clutch) and a spring type clutch.

[0047] The rotational apparatus may be changed to any apparatus that operates in accordance with power input from outside such as a hydraulic pressure pump for a brake assisting apparatus, a hydraulic pressure pump for a power steering apparatus, or an air pump for an air suspension apparatus.

[0048] The rotational apparatus unit of the present invention may be applied for purpose other than the use in wheeled vehicles such as for the use in ships.

[0049] Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. 

1. A rotational apparatus unit comprising: a rotational apparatus, wherein the rotational apparatus has a housing and a drive shaft supported by the housing; and a motor for driving the drive shaft in accordance with electric current supplied from outside, and wherein the motor is located on a periphery of the housing of the rotational apparatus such that an axis of the motor is coaxial with an axis of the drive shaft.
 2. The unit according to claim 1, wherein the rotational apparatus is connected to an engine via a power transmission mechanism, wherein, when the engine drives, the drive shaft is driven by power from the engine and, when the engine stops, the drive shaft is driven by power from the motor.
 3. The unit according to claim 2, wherein the rotational apparatus is accommodated in the housing, wherein the rotational apparatus has a driving mechanism, which is driven by the drive shaft, wherein the housing has a large diameter portion, which accommodates the driving mechanism, and a small diameter portion, which supports the power transmission mechanism, and wherein the motor is located to surround at least a part of the large diameter portion.
 4. The unit according to claim 2, wherein the power transmission mechanism includes a mechanical device, wherein the mechanical device permits power transmission from the engine to the rotational apparatus and prevents power transmission from the motor to the engine.
 5. The unit according to claim 1, wherein the rotational apparatus is a compressor, which is a part of a refrigerant circuit of an air conditioner.
 6. The unit according to claim 1, the motor comprising: a stator fixed on the periphery of the housing; a rotor located rotatably on the periphery of the housing; and a fan located in the rotor..
 7. The unit according to claim 1, the motor comprising: a stator fixed on the periphery of the housing; and a rotor located rotatably on the periphery of the housing, wherein the rotor faces the stator and is generally aligned with the stator in the axial direction of the drive shaft.
 8. A rotational apparatus unit connected to an engine via a power transmission mechanism, the rotational apparatus unit comprising: a rotational apparatus, the rotational apparatus has a housing and a drive shaft supported by the housing, wherein the drive shaft rotates by power of the engine; and a generator, which is driven by power of the engine for generating electricity, wherein the generator is located on the periphery of the housing of the rotational apparatus such that an axis of the generator is coaxial with an axis of the drive shaft.
 9. The unit according to claim 8, wherein the rotational apparatus is accommodated in the housing, wherein the rotational apparatus has a driving mechanism, which is driven by the drive shaft, wherein the housing has a large diameter portion, which accommodates most of the driving mechanism, and a small diameter portion, which supports the power transmission mechanism, and wherein the motor is located to surround at least a part of the large diameter portion.
 10. The unit according to claim 8, wherein the rotational apparatus is a compressor, which is a part of a refrigerant circuit of an air conditioner.
 11. The unit according to claim 8, the generator comprising: a stator fixed on the periphery of the housing; a rotor located rotatably on the periphery of the housing; and a fan located in the rotor.
 12. The unit according to claim 8, the generator comprising: a stator fixed on the periphery of the housing; and a rotor located rotatably on the periphery of the housing, wherein the rotor faces the stator and is generally aligned with the stator in the axial direction of the drive shaft.
 13. A rotational apparatus unit used for an air conditioner for a vehicle, wherein the rotational apparatus unit is connected to an engine, the unit comprising: a compressor, wherein the compressor has a housing and a drive shaft supported by the housing; and a motor-generator, wherein, when the engine drives, the drive shaft is driven by power of the engine and the motor-generator is driven to generate electricity, wherein, when the engine stops, the generator portion drives the drive shaft in accordance with electric current supplied from outside, and wherein the motor-generator is located on a periphery of the housing of the rotational apparatus such that an axis of the motor-generator is coaxial with an axis of the drive shaft.
 14. The unit according to claim 13, the motor-generator comprising: a stator fixed on the periphery of the housing; a rotor located rotatably on the periphery of the housing; and a fan located in the rotor.
 15. The unit according to claim 13, motor-generator comprising: a stator fixed on the periphery of the housing; and a rotor located rotatably on the periphery of the housing, wherein the rotor faces the stator and is generally aligned with the stator in the axial direction of the drive shaft. 